Final answer:
By calculating the unit rate of 40 words per minute, we can multiply that by 10 minutes to find that Jobanna can type 400 words in 10 minutes.
Step-by-step explanation:
The student's question involves calculating the number of words Jobanna can type in 10 minutes based on a given unit rate. The subject of this question is Mathematics, and it deals specifically with rates and proportional reasoning, which is a common topic in Middle School math classes.
First, let's find how many words Jobanna types per minute:
120 words in 3 minutes means the unit rate is:
- 120 words ÷ 3 minutes = 40 words per minute.
Now that we know the unit rate, we can calculate how many words she would type in 10 minutes:
- 40 words/minute × 10 minutes = 400 words.
Therefore, the correct answer is a. 400 words.